Migratory birds prefer organic

Going organic isn’t just a popular choice for eco-savvy dieters, turns out migratory birds like it too. A new study out of Lund University in Sweden shows that migrating birds lean towards green when it comes to large-scale monoculture farms, with higher abundances and diversity of birds choosing to stop at organic farms than conventional ones. The findings offer new crops for thought when it comes to managing agriculture for wildlife well-being.

The idea that organic farming is good for wildlife is nothing new. Farming practices that hit overdrive and heavy pesticide use have been linked to drops in wildlife populations. But previous studies focused largely on bugs or resident bird populations. Juliana Dänhardt and Martin Green of Lund University decided to take the research a step further, focusing on migratory bird species.

Migratory birds get hit with a double whammy when dealing with environmental stress. They contend with a lot of the same environmental pressures as resident birds, but enjoy the added baggage that comes from moving into a temporary living situation. These visitors tend to show up at tilling time to an unfamiliar landscape and must fuel up in a hurry before embarking on the next leg of their journey.

Dänhardt and Green wanted to see if organic farming and more diverse cropland would helped alleviate some of these pressures. In 2005, they and their team selected a dozen pairs of farms in Falsterbo, Sweden, one of the richest agricultural regions of the country. The pairs were set up to compare organic versus conventional and diverse versus simple crop farms. During the fall migratory season, they conducted bird surveys to see what happened. Dänhardt and her colleagues found the relationship between birds and farm preference to be a complicated one.

The strength of bird populations was all over the show. Some types of birds did prefer diverse organic farmland, while others were less discerning. And certain species, such as geese and golden plovers, showed a penchant for wide-open monoculture fields. But one overarching trend did emerge from the complexity. Turns out, birds that chose the wide-open fields also preferred the organic version.

At the moment, ag trends in Sweden lean towards encouraging crop diversity as a way to bolster wildlife populations, but this study indicates that supporting organic or low-impact farming practices on large-scale monoculture farms could be another method for helping out those hard-flying, fast-eating, stressed out migratory birds.

The study is published in the online early edition of the journal Oikos.